My suggestion would be to install a properly rated bumper that has a receiver for pulling a trailer in the rear. Properly set up you will get attachment to the frame on both sides, as well as additional straps underneath. Then you run the shakle/d-ring in the receiver with a proper attachment, and your pulling will be better distributed across the entire rear frame area.
My Jeep came with the "factory" tow package which was a lesser class ball on the back, with tow hooks up front mounted atop the frame on each side, through the factory bumper holes. I did pull folks out with a recovery strap on the old ball setup, and even on the front hooks. But I would have never tried to use a kinetic type strap on either old setup trying to pull a full size vehicle from a bad stuck. Too easy to torque the frame. With a winch installed properly on the front, and/or a proper receiver hitch in the back, the forces would be distributed better across the entire frame. The bumper will beef up your stock crossmember.
The snatch block is just a single pully that can be used with a winch line or even a come-along line to "double" your pulling power, but it also halves the length and speed. When you are researching this, check on the Quadratrac or 4WD web site and you will see the goodies. Check out earth anchors (or deadmans) because this might provide a solution to anchoring your Jeep if winching someone else out, or provide a tie point for winching yourself out. I have also seen these listed in boating supply places as a place to drive your tie off line into the sand for anchoring a boat on the beach.